Process of manufacturing sodium sulfid.



UNITED STATES PATENT Patented March 22, 1904.

OFFICE.

JOHN FLEMING 'WHITE, OF BUFFALO, NEW YORK, ASSIGNOR TO GENERAL CHEMICALCOMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF MANUFACTURING SODIUM SULFID- SPECIFICATION forming part ofLetters Patent No. 755,201, dated March 22, 1904:.

Application filed December 27, 1902. Serial No. 136,782. (No specimens.)

To all whom, it may concern:

. facturing sodium sulfid with the aid of coal.

Niter cake is obtained as a by-product in many chemical worksmanufacturing acids and is for the most part acid sodium sulfate,(NaHSOQ It is very cheap.

According to my invention the crude acid sodium sulfate, commonly knownas niter cake, and salt are mixed with coal, and the reaction is broughtabout by heating the mixture in an open furnace or other suitableapparatus. The salt (NaOl) acts on the acid sulfate of sodium (NaHSOi)and forms neutral sulfate of sodium and hydrochloric acid. The sulfateof sodium (NazSOi) is then reduced to sodium sulfid (NagS) by the actionof the coal. A general idea of the action of the salt and coal on pureacid sodium sulfate may be obtained from the following chemicalequations:

NaHSOi+NaOl Na2SOi+ H01. Na2SO4+ 2G I Na2S-l-2CO2.

The carbonic dioxid (CO2) is reduced to carbonic monoxid (CO) by thereducing action of the excess of coal which is added in my process overthat required by the above chemical equation. The sodium sulfid istherefore not decomposed by the carbonic dioxid, (002.)

An example of my process is given as follows: Six parts of niter cakeare mixed with two parts of salt and four and one-fourth parts of coal(all parts being by weight) and heated in an open furnace or othersuitable heating apparatus. The mixture becomes a thin paste or liquid.The reaction begins promptly and progresses rapidly when the temperatureis increased to incipient red heat.

The operation is completed in about two hours.

It will be observed that hydrochloric acid is formed as a by-product,and this adds to the value of my improved process. If theabove-described mixture is heated in a closed mufiie-furnace, thehydrochloric acid can be saved.

The main advantage of this method is the use of cheap niter cake, whichis awaste product in many acid-factories, for the production of sodiumsulfid.

I claim as my invention and desire to secure by Letters Patent- Theprocess of producing sodium sulfid, which consists in heating niter cakein the presence of coal and salt.

JOHN FLEMING WHITE.

Witnesses:

THEo. V. FOWLER, EMiLE V. PINCOTT.

